Ideal 36 265 36265 BUL Z EYE 5 Piece Plumbers Self Feed Drill Bit Kit Set includes 1-3/8, 1-1/2, 2-1/8, 2-9/16, 5-1/2 extension Superior cutting speed and ultra clean holes with dual cutting heads 50% wider cutting surface, clean and balanced cutsPrecision ground teethLead screw with burr free threads feeds the bit through the wood at a consistent ratePrecision machined shaft for bit eliminates wobble and makes a truer holeHeat treated and hardenedBlack oxide finishFast secure change out via a quick change arbor